Cunning Nightbonder

Flash
Spells with flash you cast cost {1} less to cast and can't be countered.

Thoughtseize

Target player reveals their hand. You choose a nonland card from it. That player discards that card. You lose 2 life.

Drowned Catacomb

This land enters tapped unless you control an Island or a Swamp.
{T}: Add {U} or {B}.

Murkwater Pathway

Clearwater Pathway

Clearwater Pathway // Murkwater Pathway

Ashiok's Erasure

Flash
When this enchantment enters, exile target spell.
Your opponents can't cast spells with the same name as the exiled card.
When this enchantment leaves the battlefield, return the exiled card to its owner's hand.

Omen of the Sea

Flash (You may cast this spell any time you could cast an instant.)
When this enchantment enters, scry 2, then draw a card.
{2}{U}, Sacrifice this enchantment: Scry 2. (Look at the top two cards of your library, then put any number of them on the bottom and the rest on top in any order.)

Torrential Gearhulk

Flash
When this creature enters, you may cast target instant card from your graveyard without paying its mana cost. If that spell would be put into your graveyard, exile it instead.

Slitherwisp

Flash
Whenever you cast another spell that has flash, you draw a card and each opponent loses 1 life.

Petty Theft

Return target nonland permanent an opponent controls to its owner's hand.

Brazen Borrower

Flash
Flying
This creature can block only creatures with flying.

Brazen Borrower // Petty Theft

Watery Grave

({T}: Add {U} or {B}.)
As this land enters, you may pay 2 life. If you don't, it enters tapped.

Brineborn Cutthroat

Flash (You may cast this spell any time you could cast an instant.)
Whenever you cast a spell during an opponent's turn, put a +1/+1 counter on this creature.

Mutual Destruction

This spell has flash as long as you control a permanent with flash.
As an additional cost to cast this spell, sacrifice a creature.
Destroy target creature.

Ebondeath, Dracolich

Flash
Flying
Ebondeath enters tapped.
You may cast this card from your graveyard if a creature not named Ebondeath, Dracolich died this turn.

Island

Lazotep Plating

Amass Zombies 1. (Put a +1/+1 counter on an Army you control. It's also a Zombie. If you don't control an Army, create a 0/0 black Zombie Army creature token first.)
You and permanents you control gain hexproof until end of turn. (You and they can't be the targets of spells or abilities your opponents control.)